HFSM Self Transition

[Chippychap]

#696 introduced ifsm_state::Self_Transition for the FSM implementation, but not for the HFSM implementation.
Expected behavior is to also reactivate (exit, enter) the current state when ifsm_state::Self_Transition is returned by process_event / on_event
Now, this may be a bit more complex as there are also parent state handling to take care of. As what should happen if the parent returns the ifsm_state::Self_Transition variable. Should than the parent be reactivated as well?

Also, but this may need to be a different issue but somewhat related. Returning the STATE_ID from the parent when it processes an event causes some weird transitions as it partially reactivates the states.
For example, in the motor control example if the Running state would accept the SetSpeed event and returns the STATE_ID. It would then reenter the Running state without exiting it first and activate its initial substate WindingUp